THURSDAY: The Ostrich – the Biggest and the Fastest

20 March 2014

Australia has its emu, and America has its rhea. You only have to look at an emu or rhea to recognize these large birds as the cousins of the familiar ostrich.  And Africa’s ostrich is the biggest and the fastest.

[Ostrich image]

The common ostrich is the biggest bird on earth growing as tall as 9 feet and weighing up to 240 pounds.  Faster than either of its cousins, ostriches have been clocked at 43 mph.  At that speed, the ostrich isn’t just the fastest bird on earth; it’s the fastest of any land animal on the planet.  Perhaps, speed compensates for flight.  Like the other members of its intercontinental family, the ostrich is a flightless bird.

[Ostrich video]

The ostrich has flashier feathers than either of its cousins.  Adult male ostriches are black with a white wing tips and white tail feathers.  Females and young males have grayish-brown feathers – similar to those of their American cousin, the rhea.  The head and neck of the ostrich . . . well, . . . it looks like the bird is going bald — with only a sparse cover of “down.”   But, instead of a comb-over, the ostrich’s thin hair stands straight up.  It looks like it had a crew cut and, then, let it grow out.

Nature has given the ostrich all it needs to keep an eye on things.   The bird’s head rises 9-feet into the air.  Its eyes are 2 inches wide — the largest eyes of any land vertebrate (land animal with a back-bone).

Ostriches spend most of their time roaming in pairs.   Sometimes, during dry spells, these large birds form flocks.  Ostriches eat plants, but will also chow-down on some insects.  You’d expect the ostrich to be a daytime-animal like most birds.   But, if you’re wandering around in the wilds of Africa, on a moonlit night, you might meet an ostrich.  The moon gives enough light to make the ostrich comfortable enough for a nocturnal prowl.

When threatened, the ostrich will lie flat on the ground to fool passers-by into thinking it is nothing more than a bump on the ground.  But there’s one old story about the ostrich that isn’t true: this bird never hides its head in the sand.  When threatened, ostriches seem to prefer to just hide – as a first line of defense.  But, when push comes to shove, these birds are more than able to defend themselves.  Ostriches use their powerful legs to kick.  And they have quite a kick.  It can be fatal.

Speaking of legs, no discussion of the ostrich would be complete without a discussion of this bird’s toes.  Yes, toes.  The ostrich’s relatives, the emu and the rhea, are both unusual birds because they have only three toes.  Most birds have four toes – three forward and one “opposing” toe.  The opposing toe is used to help the bird hang on to branches and other perches in the wild.    Of course, if you’re a bird, and you don’t fly, you don’t perch.  Flightless birds like the emu and rhea use their feet to walk and run.  To a running bird, a fourth toe would be nothing but an irritation.

It seems only logical that the ostrich should also have three toes, but it’s hard to count the number of ways in which this particular family of birds is unusual.  And, if you count the toes, you’ll find that the ostrich has only two.  Also, you’d think if you had toes, they’d be a bit alike.   Again, this family is unusual.  One toe has an enormous nail that resembles a hoof.   The other toe has no nail at all.  The best guess is that this “reduced number of toes” helps the ostrich run even faster.

[Ostrich feet]

But before we leave the subject of the ostrich’s legs, we need to say a few words about predators.  Africa is no place for any animal that can’t defend itself.  Aside from the famous “king of the jungle,” the lion, the rest of the list includes cheetahs, leopards, and hyenas as just a few of the most ferocious predators from which the ostrich has to defend itself.  Surprisingly, this bird does an amazingly good job of defending itself and can more than hold its own in the jungle.  How, does it manage?  With its legs.  The ostrich uses its legs to defend itself in two very different ways.

First, “he who fights and runs away will live to fight another day.”  The ostrich often runs away from predators.  As the fastest land animal on earth, it’s got a built-in advantage in this department.   Unfortunately, young ostriches, which haven’t grown up to their full speed, are particularly vulnerable to predators that the adult birds can easily outrun.  Sometimes, predators succeed by ambushing the ostrich – hiding and pouncing on an unsuspecting bird.  The cheetah is not as fast as an ostrich but, sometimes, is fast enough to catch an ostrich before the bird can build-up to full speed.

Second, the ostrich can use its legs to fight.  When an ostrich can’t retreat, especially when defending its nest, it will use its legs against an attacker.  With all of its running, you might get the impression that the ostrich isn’t an effective fighter.  It almost seems inaccurate to say the ostrich uses its legs to defend itself, because its legs are so often fatal to its adversary.  Maybe it’s enough to say that ostriches can, and do, kill lions with their legs.

In the wild, ostriches avoid humans as potential predators.  Maybe it’s a good thing for humans that the ostrich prefers to run away.  Ostriches in the wild, and sometime in captivity, can attack humans if these birds feel threatened.  Human deaths occur each year from massive injuries from a single kick of a leg and a single swipe of a claw.  These birds are big and tough.

Of the members of this family, the ostrich, emu, and rhea, the mating behavior of the ostrich is “about in the middle” in terms of strangeness.  Like the rhea, during mating season, a single ostrich male will mate with as few as 2 or as many as 7 females.  Although the male mates with several females, it will form a couple – a bond – with only one of the females in the group.

The strangeness of ostrich mating involves its rituals.  The male will repeat a loud, booming call while doing a kind of dance in which it flaps one wing a few times and, then, the other a few times.  The female will run in a circle around the male, while the male winds his head in a spiral motion. Disturbingly, ostriches raised entirely by humans will direct these same rituals toward their human keepers.

Females lay their eggs in a shared nest.  Ostriches lay the largest eggs of any bird at about 6 inches in length and 3 pounds in weight.  The males sit on the eggs at night and, then, the females sit on the eggs during the day.   The eggs hatch in about 40 days.  The male principally defends the hatchlings and teaches them to feed, but both the male and female raise their young together.

[Ostrich family on a walk]

The young ostriches will not reach full maturity in less than 2 years and, if they survive predators until they reach adulthood, a large number can expect to live for many more years.  Ostriches have been known to live past 60 years of age.

Ostriches have always been a focus of human fascination.  Use of their feathers for ornamentation extends back almost to the beginning of recorded history.  However, only in the 19th century did commercial ostrich farming for feathers develop.   These giant birds where tamed by capturing baby ostriches and raising them in captivity.  Ostriches, by the way, aren’t plucked, but sort of sheared.  A new crop of feathers re-grows about every 8 months.  The ostrich industry was only about feathers until the 1970’s when ostrich skin/leather and ostrich meat became profitable products.

Also, ostrich racing is catching on.  In Africa, people race ostriches while riding on the birds’ backs.  The “riding-birds” are specially fitted with saddles, reins, and bits for the purpose.  In the United States, ostrich racing began in Jacksonville, Florida, with the ostriches pulling draw-carts with human occupants.  Now, races are not only held in Florida, but also in Arizona, Nevada, and Minnesota.

[Ostrich racing]

THURSDAY: The Emu – Green Eggs, But No Ham

20 March  2014

[emu]

Africa has its ostrich, and America has its, lesser known, rhea.  But Australia has its emu.  On first sight, this large, grey-brown bird is unmistakably the close relative of both the ostrich and rhea.  However, the emu is the “character” of the family — the odd one in this not so typical family of birds.

[image]

Like its cousins, the emu is a flightless bird.  And, also, like it cousins, it’s fast.  So, even if it can’t fly, it can run faster than any other animal in Australia.  At 31 miles per hour, the emu ranks as the second fasted bird on earth — second only to its African cousin, the ostrich.  At a height reaching up to a bit over six-and-a-half feet and weighing as much as 130 pounds, the emu enjoys the distinction of being the largest bird in Australia.  But, again, in terms of size, the emu is only the second largest bird in the world.  The largest?  You guessed it.  Cousin Ostrich.

Although sharing the ostrich’s unmistakable form and profile, in terms of appearance, the emu is not only smaller than its African cousin, but has brown colored plumage –  just a touch drabber than the grey-brown feathers of its other cousin, the Rhea.  Maybe to make up for its drab feathers, nature has favored the emu with a blue neck.   This relatively bright “collar” give the bird a bit of color while allowing it to conceal itself by lowering its head and neck for purposes of camouflage.

Camouflage?  This bird is over 6 feet tall.  Who’s going to mess with it?  Actually, the emu has predators in the wild, unpopulated “Outback” of Australia.   Both eagles and hawks attack emus from the air.   But there’s a catch.  The emus that are grabbed and carried off by eagles and hawks are young birds that have not yet reached their adult height and weight.

Could a flying bird carry off a full grown emu?  Well, even in the Out-est of the Outback, there are no birds that big.  The young victims have few defenses beyond their speed and a peculiar swerving run they share with Cousin Rhea.  At times, Emus extend their relatively small wings to keep their balance as the run in an evasive swerving pattern.

Dingos, a member of the grey wolf family, are the only predator of the full grown bird.  Even if emu’s lose some fights for survival with this free ranging dog of the Outback, the emu brings a serious weapon to the fight – its feet.

Like Cousin Rhea, the emu has 3 toes on its clawed feet.  This is unusual for birds, which often have a fourth “opposing” toe used to grip branches and other natural perches.   Three toe, tridactyl, clawed feet are found in birds that, like the emu, walk and run on flat ground instead of flying.  And the emu has really big, mean clawed feet.  Mean?  Yes, mean.  Emus have been known to use their feet to rip through wire fences.  You really don’t want to get these birds angry or get in their way when they’re going somewhere.

[image]

And emus like to get where they’re going.  Not favoring flocks, these birds often travel in pairs.  They run at high speed and are unruffled by water.  When a body of water comes between an emu and where it wants to go, it just jumps in and swims.

When these birds aren’t running or swimming, they pause to feed on a variety of insects and plants.  They have excellent eye-sight.  When they’re not eating, they like to groom or “preen” their “plumage” or look around and “investigate.”

Noted for their curiosity, emus will approach humans – especially if they see movement or a colorful piece of clothing.  These birds have been known to follow and watch humans in the wild.  And, once you attract an emu’s attention, it might not be so easy to give an interested bird “the slip.”   Hoping that an emu will go away if you “just ignore it” doesn’t always work.   And, be warned: emus seem to have a sense of humor.  They have been known to approach humans and other animals and poke them with their beak and, then, run away.  Observers have the impression that this is a kind of “game” for the large bird.

The emu’s “call” is not like a bird’s call at all.  The emu makes a loud drumming or thumping sound.  That’s all.  And . . .  did I say it was loud?  It can be heard a little over a mile away.  The emu’s call enjoyed its 15 minutes of fame on the animated television series, King of the Hill .   In one episode, (Season 6, Episode 17, “Fun with Jane and Jane”), the emus “sing” the theme song with the closing credits.  Of course, there’s no music involved.  The animated birds simply intone a series of loud thumps in lieu of the regular theme.

Although there is no recognizable difference in appearance that distinguishes the male from the female.   But emus generally roam in pairs.  The pair consists of one male and one female.  But this pairing ends, more or less, with mating season.  Wait . . . the male-female pairing ends with mating season?  Yes.  It’s strange.  But that’s only the beginning of the strangeness.

Emus don’t abandon the male-female stereotypes in mating.  They reverse them.

During mating season, the females become aggressive and begin to court the relatively passive males.  A female will circle around the potential male mate drawing closer and closer.  If another passing female develops an attraction for the same male, it may, and often does, start a fight.  During mating season, fights among females are common with a single fight sometimes lasting for hours.

After mating, the male builds its nest.  And it is the male’s nest.  The female will lay eggs in the nest, but not sit on the eggs.  The male cares completely for eggs, and will lose about a third of his body-weight because of its inability to leave the nest and obtain food.   After laying her eggs, the mating female will often seek out another male, mating with as many males as possible during the mating season.

The emu’s eggs are . . . interesting . . . because they are large: over 5 inches long and weighing as much as 2 pounds.  Also, they are green.  When freshly laid, the emu’s eggs are a light green.  You might ask, “Then, they turn white, right?”  No, they don’t.  They get greener and greener until they reach the shade of an avocado.

[image]

The eggs hatch about 56 days after they are laid.  The newly hatched chicks weigh a little over a pound and are about 5 inches tall.  They can leave the nest within days, but will stay with their defending father for about 6 or 7 months learning how to find food and reaching their full adult size.  However, the young can spend as long as a year in this family circle before taking off on their own.  An emu can live as long as 20 years.

[image]

Emus are raised for meat in Australia, the United States, Peru, and China. The USDA classifies emu as red, poultry meat.  Emu skin is used to produce a distinctive type of leather.  Oil from emu fat is used for cosmetics and dietary supplements.  Although emu oil has a long history of use as an anti-inflammatory, therapeutic product, the US FDA has classified emu oil as an “unapproved drug.”

The emu is prized as a cultural icon in Australia appearing with the red kangaroo on the Coat of arms of Australia and the Australian 50 cent coin.   The bird has been featured on a number of Australian postage stamps and is the namesake of mountains, lakes, towns and even a brand of beer.